prog1.m:3:34: error: Foundation/Foundation.h: No such file or directoryprog1.m: In function ‘main’:prog1.m:7: error: ‘NSAutoreleasePool’ undeclared (first use in this function)prog1.m:7: error: (Each undeclared identifier is reported only onceprog1.m:7: error: for each function it appears in.)prog1.m:7: error: ‘pool’ undeclared (first use in this function)

I have checked the program, and can't find a mistake in the program. I have no idea what I am doing wrong.